Call initiation message delay during handoff process

ABSTRACT

A network gateway receives a voice over long term evolution (VoLTE) call establishment request from an internet protocol (IP) multimedia services (IMS) core network for a mobile device. The network gateway queries a serving gateway to determine whether the mobile device is transitioning from a first evolved node B (eNB) to a second eNB. If the mobile device is transitioning, based on the existence of a user plane modify request, the network gateway delays forwarding the received request to a mobility management entity until the serving gateway informs the network gateway that the serving gateway received a first data packet from the mobile device via the second eNB as an indication the transition is complete.

BACKGROUND

In recent years, mobile wireless communications have become increasinglypopular. Currently, mobile networks are operational that conform withthe fourth generation (4G) standards, such as the Long Term Evolution(LTE) standard. These mobile networks provide voice communication,messaging, email and internet access (for example) by using radiofrequency communication. Increasingly, mobile network operators aredeploying Voice over LTE (VoLTE) capabilities within their mobilenetworks. VoLTE utilizes a dedicated bearer channel between a mobiledevice and a packet data network (PDN) gateway (PGW) to deliver voice(and/or video) as data packets to/from the mobile device.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord withthe present teachings, by way of example only, not by way of limitation.In the figures, like reference numerals refer to the same or similarelements.

FIG. 1 is a functional block diagram of an example of a system which mayprocess a handoff event and establishing a dedicated bearer channel.

FIG. 2 is a flow diagram of an example of processing a handoff event andestablishing a dedicated bearer channel as implemented by the systemrepresented by FIG. 1.

FIG. 3 provides a block diagram of a general purpose computer hardwareplatform that may be configured as a host or server, for example, tofunction as any of the server computers or eNodeBs shown in FIG. 1.

FIG. 4 is a simplified functional block diagram of a personal computeror other work station or user terminal device.

DETAILED DESCRIPTION OF EXAMPLES

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and/or circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

A mobile wireless communication network that supports the long termevolution (LTE) standard carries all traffic, for example, as packets ofdata, typically conforming to the internet protocol (IP) standard. Whena mobile device connects to such a mobile network, the mobile networkestablishes, for example, a default bearer channel on behalf of themobile device over which traffic destined to/from the mobile device willpass. Unlike prior circuit switched networks where a physical or logical(e.g., timeslot based) circuit was utilized, a bearer channel in a LTEmobile network is, for example, a virtual tunnel or template defininghow elements within the LTE mobile network will handle traffic assignedto and/or matching the virtual tunnel/template. Thus, the default bearerchannel, in this example, is a definition of how to handle packets oftraffic to/from the mobile device by elements of the LTE mobile network,typically using a best effort quality of service (QoS).

Typically, traffic to/from a mobile device connected to a LTE mobilenetwork will utilize a default bearer channel. When there will be a callinvolving voice communications, e.g. a voice or video call, to or fromthe mobile device, there is an exchange of signaling to establish thevirtual call connection through the network and over the air with themobile device. Current LTE/IMS networks use session initiation protocol(SIP) for at least some of the signaling messages. During call set-up,the signaling messages utilize the default bearer channel.

Because the default bearer channel is, for example, only a best effortQoS, the default bearer channel is insufficient to carry trafficrequiring a higher QoS (e.g., voice, video). As such, after a voice callis established with the mobile device connected to the LTE mobilenetwork (e.g., voice over LTE (VoLTE)), an IP multimedia services (IMS)core network involved in establishing the voice call may request, forexample, that the LTE mobile network establish a dedicated bearerchannel (e.g., virtual tunnel/template with higher QoS). In thisexample, subsequent voice traffic packets associated with the VoLTE callmay pass over the established dedicated bearer channel (e.g., elementsof the LTE mobile network will treat the VoLTE call with a higher QoS).As can be seen from this example, the signaling messages used toestablish the call typically use the default bearer channel while thevoice (and/or video) packets of the established VoLTE call typically usethe dedicated bearer channel.

Normally, when the request to establish the dedicated bearer channel forthe VoLTE call is received from the IMS core network by a packetgateway, such as a packet data network gateway (PGW) of the LTE mobilenetwork, the packet gateway (e.g., PGW) forwards the request to amanagement node, such as a mobility management entity (MME) of the LTEmobile network, and the management node directs a serving gateway, suchas a serving packet data network gateway (SGW) currently serving themobile device, to establish the dedicated bearer channel between theserving gateway (e.g., SGW) and the mobile device via a first wirelessnetwork node, such as an evolved node B (eNodeB). However, if the mobiledevice is transitioning away from and is no longer associated with thefirst wireless network node, establishment of the dedicated bearerchannel will fail. This dedicated bearer channel establishment failuremay cause the VoLTE voice call traffic to lack a sufficient higher QoSand call quality may be impacted.

The examples described in detail below relate to techniques for delayingestablishment of a dedicated bearer channel to support a VoLTE call(e.g., requiring a higher QoS, such as a voice and/or video call) when amobile device is transitioning between two wireless network nodes (e.g.,eNodeBs) until after the transition is complete. In one example, amobile device is transitioning between a first wireless network node anda second wireless network node. During the transition (e.g., handoff,handover), a management node (e.g., MME) records the mobile device asstill being associated with the first wireless network node. When thetransition is complete, in this example, the management node is updatedto reflect that the mobile device is associated with the second wirelessnetwork.

In a further example, when a packet gateway of the mobile wirelesscommunication network (e.g., PGW) receives, from an IMS core network, arequest to establish a dedicated bearer channel to support a VoLTE call,the packet gateway (e.g., PGW) first queries a serving gateway (e.g.,SGW) to determine whether the mobile device is transitioning. If themobile device is transitioning, in this example, the serving gateway(e.g., SGW) may have received a user plane modify request from themobile device and the serving gateway will notify the packet gateway ofsuch user plane modify request in response to the packet gateway'squery. The user plane modify request is, for example, an indication fromthe mobile device that the mobile device is transitioning between twowireless network nodes, as described in greater detail below. Uponreceiving the response indicating that the mobile device istransitioning, the packet gateway (e.g., PGW) delays forwarding therequest from the IMS core network to the management node until thepacket gateway receives an indication that the transition is completefrom the serving gateway. The serving gateway, in this further example,learns that the transition is complete when the serving gateway receivesa first data packet from the mobile device via the second wirelessnetwork node. In this way, the management node typically will notreceive the request to establish the dedicated bearer channel untilafter the transition is complete and the management node has beenupdated with a record indicating the mobile device is associated withthe second wireless network node. When the management node receives thedelayed dedicated bearer channel establishment request, the managementnode instructs the serving gateway, for example, to establish thededicated bearer channel between the serving gateway and the secondwireless network node to which the mobile device is now associated.

Reference now is made in detail to the examples illustrated in theaccompanying drawings and discussed below. FIG. 1 is a functional blockdiagram of an example of a system 10 that supports various mobilecommunication services and which may implement processing forestablishing a dedicated bearer channel during a handover event.

The illustrated system 10 services any number of mobile devices,including the illustrated mobile device 14. Mobile device 14 may be alaptop, a personal digital assistant (“PDA”), a smartphone, a tablet PCor another portable device designed to communicate via a wirelessnetwork. Mobile device 14 in the example corresponds to a smartphone ortablet itself having network communication capability. Although notshown for simplicity, the present dedicated bearer establishment duringhandover techniques also may be used with other types of devices, forexample, mobile broadband devices like Jetpacks or USB dongles thatprovide service connectivity for other types of data devices (e.g.non-mobile/wireless computers or the like).

A carrier offering long term evolution (LTE) and voice over LTE (VoLTE)mobile services operates a network having equipment forming a portion ofthe network supporting LTE services. Although various networkarchitectures may be used to form the network, the drawing shows anarrangement using one or more wireless access networks 15 and a corenetwork 16, operated by one mobile carrier. Hence, the illustratedsystem example includes a mobile communication network 10, in this case,operated in accordance with 4G LTE standards. Mobile network 10 mayprovide mobile telephone communications as well as Internet datacommunication services. For example, mobile network 10 may connect tothe public switched telephone network (PSTN, not shown) and publicpacket-switched data communication networks such as the Internet 23 viapacket data gateway (PGW) 54. Data communications via mobile network 10provided for users of mobile devices 14 may support a variety ofservices such as communications of text and multimedia messages, e-mail,web browsing, streaming or downloading content, etc. with networkconnected equipment such as a server 25 and/or laptop computer 27 in thedrawing. Voice communication also may involve transport via the Internet23 using voice over Internet Protocol (VoIP) technologies.

Mobile device 14 may connect to mobile network 10 through wirelessaccess network 15 via wireless network nodes such as eNodeBs 18A, 18B,two of which appear in the drawing by way of example.

The illustrated system 10 can be implemented by a number ofinterconnected networks. Hence, the overall network 10 may include anumber of wireless access networks 15, as well as regional groundnetworks interconnecting a number of wireless access networks and a widearea network (WAN) interconnecting the regional ground networks to corenetwork elements. A regional portion of the network 10, such as thatserving mobile device 14, can include one or more wireless accessnetworks 15 and a regional packet switched network and associatedsignaling network facilities.

Physical elements of a 4G LTE wireless access network 15 include anumber of nodes referred to as eNodeBs represented in the example byeNodeBs 18A, 18B. Although not separately shown, such an eNodeB caninclude a base transceiver system (BTS), which can communicate via anantennae system at the site of eNodeB and over the airlink with one ormore mobile devices 14, when any mobile device is within range. EacheNodeB can include a BTS coupled to several antennae mounted on a radiotower within a coverage area often referred to as a “cell.” The BTS isthe part of the radio network that sends and receives RF signals to/fromthe mobile device 14 that is served by eNodeB 18A, 18B. Such eNodeBs18A, 18B operate in accordance with the more modern LTE networkstandard, sometimes referred to as 4G and/or 4G LTE. Packet routing andcontrol functions may be implemented in packet routers and/or associatedserver platforms in the wireless access network or in many cases inelements of an IP Multimedia Service (IMS) core network 51 coupled tosome number of 4G wireless access networks 15 via core network 16,although such routing and control element(s) are generically included inthe broad class of devices that may be used to implement the networkfunctionality discussed here.

The wireless access network 15 interconnects with the core trafficnetwork represented generally by the cloud at 16 via a serving packetgateway 56, which carries the user communications and data for themobile device 14 between an eNodeB 18A, 18B and other elements with orthrough which the mobile devices communicate. The networks can alsoinclude other elements that support functionality such as messagingservice messages and voice communications. Specific elements of thenetwork 16 for carrying the voice and data traffic and for controllingvarious aspects of the calls or sessions through the network 16 areomitted here for simplicity. It will be understood that the variousnetwork elements can communicate with each other and other aspects ofthe illustrated system 10 and other networks (e.g., the PSTN (not shown)and the Internet 23) either directly or indirectly.

A mobile device 14 communicates over the air with an eNodeB 18A or 18Band through the traffic network 16 for various voice and datacommunications, e.g. through the Internet 23 with a server such as theapplication server 25. As mobile device 14 transitions between twoeNodeBs, such as eNodeB 18A and eNodeB 18B, core network 16 and wirelessaccess network 15 may utilize the techniques for delaying theestablishment of a dedicated bearer channel as described in greaterdetail below.

Mobile network 16 includes one or more mobility management entities(MMES) 52 with which the PGW 54 interacts to establish a dedicatedbearer channel during a handover of mobile device 14 between eNodeB 18Aand eNodeB 18B, such as described in greater detail in relation to FIG.2. In the LTE network 16, the MME 52 provides control and managementfunctionality while SGW 56 performs data routing between mobile device14 and PGW 54 (e.g., call data during a VoLTE call).

In one example, mobile device 14 is in proximity of and has a radioconnection with eNodeB 18A. MME 52, in this example, maintains a recordthat mobile device 14 is currently served through or “connected” toeNodeB 18A. When a VoLTE call is established through core network 16 andwireless access network 15 with mobile device 14, IMS core network 51will send a request to PGW 54 for a dedicated bearer channel to beestablished to support the VoLTE call. This request is, for example, anIP connectivity access network (CAN) session modification request. SuchIP-CAN session modification request is, for example, a diameter message.Diameter is, for example, a protocol utilized to perform authentication,authorization and accounting within a network environment. The dedicatedbearer channel is, for example, a logical or virtual path over whichpacket data associated with the VoLTE call will pass through wirelessaccess network 15 and core network 16 with a guaranteed QoS suitable forvoice communication. The dedicated bearer channel is established, forexample, between the mobile device 14 and the SGW 56 currently servingmobile device 14 via eNodeB 18A. The dedicated bearer channel alsoextends, for example, from the SGW 56 to the PGW 54.

In this example, PGW 54 will forward the request from IMS core network51 to MME 52. Based on the record that mobile device 14 is currentlyconnected to eNodeB 18A maintained by MME 52, MME 52 will prompt SGW 56to attempt to establish the dedicated bearer channel with mobile device14 via eNodeB 18A. Once the dedicated bearer channel is established, theVoLTE call can proceed and the data associated with the VoLTE call willpass over the dedicated bearer channel.

In a further example, mobile device 14 transitions between eNodeB 18Aand eNodeB 18B. For example, a user of mobile device 14 is travelingalong a road and eNodeBs 18A, 18B provide coverage for correspondingportions of the road. Such a transition is commonly referred to as ahandoff and/or handover. MME 52, however, will not update the maintainedrecord of which eNodeB mobile device 14 is currently connected to untilafter the transition (e.g., handoff, handover) is complete. Thus, therecord maintained by MME 52 will not reflect that mobile device 14 iscurrently connected to eNodeB 18B until after mobile device 14 hascompleted the transition.

In this further example, if a VoLTE call is initiated during thetransition, MME 52 will prompt SGW 56 to attempt to establish thededicated bearer channel with mobile device 14 via eNodeB 18A, but suchattempt will fail because mobile device 14 is no longer connected toeNodeB 18A. If PGW 54, however, delays forwarding the request toestablish the dedicated bearer channel from the IMS core network 51 toMME 52 until after the transition is complete, for example, MME 52 willhave an updated record and MME 52 will prompt SGW 56 to attempt toestablish the dedicated bearer channel with mobile device 14 via eNodeB18B instead of eNodeB 18A.

FIG. 2 is a flow diagram of an example of a process to delay forwardinga request to establish a dedicated bearer channel until after a mobiledevice has transitioned between two wireless network nodes.

The process starts in step 200. In step 201, PGW 54 receives a requestfrom IMS core network 51, for example, to establish a dedicated bearerchannel to support a VoLTE call corresponding to mobile device 14. Inone example, the request is an IP-CAN session modification requestwithin a diameter message requesting establishment of the dedicatedbearer channel to support an established voice call with mobile device14. At this point, PGW 54 does not know whether mobile device 14 istransitioning between wireless network nodes of mobile network 16. Instep 202, PGW 54 queries SGW 56, for example, to determine a status formobile device 14.

In one example, when mobile device 14 begins to transition between twowireless network nodes, such as eNodeBs 18A, 18B, mobile device 14generates a user plane modify request. This modify request informs SGW56 that mobile device 14 is transitioning between eNodeB 18A and eNodeB18B, for example. In response to the modify request, SGW 56 continues tomaintain a default bearer channel with mobile device 14 via eNodeB 18Aand creates a new default bearer channel with mobile device 14 viaeNodeB 18B. Once SGW 56 receives a first data packet from mobile device14 via eNodeB 18B, for example, SGW 56 determines that the transition iscomplete and destroys the default bearer channel with mobile device 14via eNodeB 18A.

As such, in step 203, SGW 56 determines whether a user plane modifyrequest for mobile device 14 exists and SGW 56 responds to the queryfrom PGW 54 with the result of the determination. If a user plane modifyrequest does not exist, the process proceeds to step 208 discussed ingreater detail below. If a user plane modify request does exist, PGW 54delays forwarding the request from the IMS core network 51 to MME 52until mobile device 14 completes the transition. As part of the delay,PGW 54 sends, for example, a notice of the delay to IMS core network 51.In one example, the delay notice is a SIP 180-trying message.

In the transition example, SGW 56 receives, in step 205, a first datapacket from mobile device 14 via eNodeB 18B and SGW 56 determines thetransition is complete. Such first data packet is received, for example,over the default bearer channel between mobile device 14 and SGW 56 viaeNodeB 18B. The first data packet is, for example, unrelated to theestablished VoLTE call or the request received by PGW 54 from IMS corenetwork 51 in step 201. In one example, the first data packet is part ofan existing data connection between mobile device 14 and SGW 56. As aresult of receiving the first data packet from mobile device 14 viaeNodeB 18B, SGW 56, in step 206, notifies PGW 54 that the transition iscomplete.

In step 208, PGW 54 forwards the request from IMS core network 51 to MME52. As discussed above, PGW 54 forwards the request, in one example,without delay because SGW 56 determined no user plane modify requestexisted for mobile device 14. In an alternate example, PGW 54 delaysforwarding the request, because a user plane modify request existed formobile device 14, until SGW 56 notifies PGW 54 that the transition iscomplete. In either example, once MME 52 receives the request in step208, MME 52 prompts SGW 56 to attempt to establish a dedicated bearerchannel through mobile network 16 between mobile device 14 and SGW 56.If the dedicated bearer channel is established, data related to theVoLTE call is passed over the dedicated bearer channel in the normalmanner. The process ends in step 210.

As shown by the description above, a variety of the related functions todelay forwarding of a request to establish a dedicated bearer channelmay be implemented on servers. Although special-built hardware may beused, server functions often are implemented by appropriate programmingto configure one or more general-purpose computer platforms that haveinterfacing to support communications via the particular network(s).

FIG. 3 provides a functional block diagram illustration of a generalpurpose computer hardware platform. More specifically, FIG. 3illustrates a network or host computer platform, as may typically beused to implement a server, such as MME 52 and/or any of the otherservers/platforms shown in FIG. 1. FIG. 4 depicts a computer with userinterface elements, as may be used to implement a personal computer orother type of work station or terminal device, although the computer ofFIG. 4 may also act as a server if appropriately programmed. It isbelieved that the general structure and general operation of suchequipment as shown in FIGS. 3 and 4 should be self-explanatory from thehigh-level illustrations.

A server or host computer hardware platform, for example as mightimplement a packet gateway, includes a data communication interface forpacket data communication (see FIG. 3). The server computer alsoincludes processor hardware forming a central processing unit (CPU), inthe form of one or more processors, for executing program instructions.The server platform typically includes an internal communication bus,program storage, and data storage for various data files to be processedand/or communicated by the server, although the server often receivesprogramming and data via network communications. The hardware elements,operating systems and programming languages of such servers areconventional in nature, and it is presumed that those skilled in the artare adequately familiar therewith. Of course, the server functions maybe implemented in a distributed fashion on a number of similarplatforms, to distribute the processing load. Although such genericcomputer configured by a program may be used to implement a packetgateway, such as PGW 54 and/or SGW 56, in some examples the packetgateway is a smart packet switch or router. For example, thecommunication ports of FIG. 3 implement a switch or routing fabric,either via specialized hardware and/or programming. The softwareprogramming relating to the location techniques discussed herein may bedownloaded and/or updated from a computer platform, for example, toconfigure the PGW or other server (e.g. FIG. 1) or from a host computeror the like communicating with the mobile device via the network (e.g.FIG. 1).

A computer type user terminal device, such as a PC or tablet computer,similarly includes a data communication interface, processor hardwareforming a CPU, main memory and one or more mass storage devices forstoring user data and the various executable programs (see FIG. 4). Amobile device type user terminal may include similar elements, but willtypically use smaller components that also require less power, tofacilitate implementation in a portable form factor. The various typesof user terminal devices will also include various user input and outputelements. A computer, for example, may include a keyboard and a cursorcontrol/selection device such as a mouse, trackball, joystick ortouchpad; and a display for visual outputs. A microphone and speakerenable audio input and output. Some smartphones include similar butsmaller input and output elements. Tablets and other types ofsmartphones utilize touch sensitive display screens, instead of separatekeyboard and cursor control elements. The hardware elements, operatingsystems and programming languages of such user terminal devices also areconventional in nature.

Hence, aspects of the techniques to delay forwarding of a request toestablish a dedicated bearer channel and related communications outlinedabove may be embodied in programming. Program aspects of the technologymay be thought of as “products” or “articles of manufacture” typicallyin the form of executable code and/or associated list data that iscarried on or embodied in a type of machine readable medium. “Storage”type media include any or all of the memory of the computers, processorsor the like, or associated modules thereof, such as varioussemiconductor memories, tape drives, disk drives and the like, which mayprovide storage at any time for the software programming. All orportions of the software may at times be communicated through theInternet or various other telecommunication networks. Thus, another typeof media that may bear the software elements includes optical,electrical and electromagnetic waves, such as used across physicalinterfaces between local devices, through wired and optical landlinenetworks and over various air-links. The physical elements that carrysuch waves, such as wired or wireless links, optical links or the like,also may be considered as media bearing the software. As used herein,unless restricted to non-transitory or tangible storage media, moregeneral terms such as computer or machine “readable medium” refer to anymedium that participates in providing instructions to a processor forexecution.

While the foregoing has described what are considered to be the bestmode and/or other examples, it is understood that various modificationsmay be made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that the teachings may beapplied in numerous applications, only some of which have been describedherein. It is intended by the following claims to claim any and allapplications, modifications and variations that fall within the truescope of the present teachings.

Unless otherwise stated, all measurements, values, ratings, positions,magnitudes, sizes, and other specifications that are set forth in thisspecification, including in the claims that follow, are approximate, notexact. They are intended to have a reasonable range that is consistentwith the functions to which they relate and with what is customary inthe art to which they pertain.

The scope of protection is limited solely by the claims that now follow.That scope is intended and should be interpreted to be as broad as isconsistent with the ordinary meaning of the language that is used in theclaims when interpreted in light of this specification and theprosecution history that follows and to encompass all structural andfunctional equivalents. Notwithstanding, none of the claims are intendedto embrace subject matter that fails to satisfy the requirement ofSections 101, 102, or 103 of the Patent Act, nor should they beinterpreted in such a way. Any unintended embracement of such subjectmatter is hereby disclaimed.

Except as stated immediately above, nothing that has been stated orillustrated is intended or should be interpreted to cause a dedicationof any component, step, feature, object, benefit, advantage, orequivalent to the public, regardless of whether it is or is not recitedin the claims.

It will be understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.Relational terms such as first and second and the like may be usedsolely to distinguish one entity or action from another withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The terms “comprises,” “comprising,”or any other variation thereof, are intended to cover a non-exclusiveinclusion, such that a process, method, article, or apparatus thatcomprises a list of elements does not include only those elements butmay include other elements not expressly listed or inherent to suchprocess, method, article, or apparatus. An element proceeded by “a” or“an” does not, without further constraints, preclude the existence ofadditional identical elements in the process, method, article, orapparatus that comprises the element.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. In addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus the following claims arehereby incorporated into the Detailed Description, with each claimstanding on its own as a separately claimed subject matter.

What is claimed is:
 1. A network device, comprising: a memory to storeinstructions; and one or more processors, coupled to the memory toexecute the instructions to: receive, from an Internet protocolmultimedia subsystem (IMS) core network, a request to establish adedicated bearer channel, through a mobile wireless communicationnetwork, between a mobile device and a serving gateway communicatingwith the mobile wireless communication network; determine whether themobile device is transitioning from a first node of the mobile wirelesscommunication network to a second node of the mobile wirelesscommunication network, the one or more processors, when determiningwhether the mobile device is transitioning, are to: provide, to theserving gateway, a query requesting whether a user plane modify requestrelated to the mobile device exists, receive, from the serving gatewayand based on the query, a response indicating whether the mobile deviceis transitioning from the first node to the second node, and determinewhether the mobile device is transitioning from the first node to thesecond node based on the response; and process the request based onwhether the mobile device is transitioning from the first node to thesecond node.
 2. The network device of claim 1, wherein the networkdevice includes a packet data network gateway.
 3. The network device ofclaim 1, wherein: the mobile device is determined to be transitioningwhen the response indicates a user plane modify request related to themobile device exists; and the mobile device is determined not to betransitioning when the response indicates no user plane modify requestrelated to the mobile device exists.
 4. The network device of claim 1,wherein, upon determining the mobile device is transitioning, the one ormore processors are further to: delay forwarding the request to amobility management entity of the mobile wireless communication network.5. The network device of claim 1, wherein the one or more processors arefurther to: send an indication of a delay to the IMS core network; andwait until receipt of an indication that the transition is completebased on the serving gateway receiving a first data packet from themobile device.
 6. The network device of claim 5, wherein the indicationof the delay is sent via session initiation protocol (SIP).
 7. Thenetwork device of claim 5, wherein the indication of the delay includesa session initiation protocol (SIP) 180-trying message.
 8. The networkdevice of claim 5, wherein, upon receipt of the indication that thetransition is complete, the one or more processors are further to:forward the request from the IMS core network to a mobility managemententity to prompt the mobility management entity to attempt to fulfillthe request.
 9. The network device of claim 1, wherein, upon determiningthe mobile device is not transitioning, the one or more processors arefurther to: forward the request from the IMS core network to a mobilitymanagement entity to prompt the mobility management entity to attempt tofulfill the request.
 10. A method, comprising: receiving, by a networkdevice and from an internet protocol (IP) multimedia services (IMS) corenetwork, a request to establish a dedicated bearer channel, through amobile wireless communication network, between a mobile device and aserving packet data network gateway within the mobile wirelesscommunication network, the request to be forwarded to a mobilitymanagement entity of the mobile wireless communication network to promptthe mobility management entity to attempt to fulfill the request;determining, by the network device, whether the mobile device istransitioning from a first node of the mobile wireless communicationnetwork to a second node of the mobile wireless communication network,determining whether the mobile device is transitioning from the firstnode to the second node including: providing, to the serving packet datanetwork gateway, a query requesting whether a user plane modify requestrelated to the mobile device exists, receiving, from the serving packetdata network gateway and based on the query, a response indicatingwhether the mobile device is transitioning from the first node to thesecond node, and determining whether the mobile device is transitioningfrom the first node to the second node based on the response; andprocessing, by the network device, the request based on whether themobile device is transitioning from the first node to the second node.11. The method of claim 10, wherein the network device includes a packetdata network gateway.
 12. The method of claim 11, wherein: the mobiledevice is determined to be transitioning when the response indicates auser plane modify request related to the mobile device exists; and themobile device is determined not to be transitioning when the responseindicates no user plane modify request related to the mobile deviceexists.
 13. The method of claim 10, wherein, upon a determination thatthe mobile device is transitioning, the method further comprises:delaying forwarding of the request to the mobility management entity.14. The method of claim 10, wherein the method further comprises:sending an indication of a delay to the IMS core network; and waitinguntil receipt of an indication that the transition is complete based onthe serving packet data network gateway receiving a first data packetfrom the mobile device.
 15. The method of claim 14, wherein theindication of the delay is sent via a session initiation protocol (SIP).16. The method of claim 14, wherein the indication of the delay includesa session initiation protocol (SIP) 180-trying message.
 17. The methodof claim 14, wherein, upon receipt of the indication that the transitionis complete, the method further comprises: forwarding the request fromthe IMS core network to the mobility management entity to prompt themobility management entity to attempt to fulfill the request.
 18. Themethod of claim 10, wherein, upon a determination that the mobile deviceis not transitioning, the method further comprises: forwarding therequest from the IMS core network to the mobility management entity toprompt the mobility management entity to attempt to fulfill the request.19. A non-transitory computer-readable medium for storing instructions,the instructions comprising: one or more instructions that, whenexecuted by one or more processors, of a network device, cause the oneor more processors to: receive, from an Internet protocol multimediasubsystem (IMS) core network, a request to establish a dedicated bearerchannel, through a mobile wireless communication network, between amobile device and a serving gateway connected to the mobile wirelesscommunication network; determine whether the mobile device istransitioning from a first node of the mobile wireless communicationnetwork to a second node of the mobile wireless communication network,the one or more instructions, that cause the one or more processors todetermine whether the mobile device is transitioning, cause the one ormore processors to: provide, to the serving gateway, a query requestingwhether a user plane modify request related to the mobile device exists,receive, from the serving gateway and based on the query, a responseindicating whether the mobile device is transitioning from the firstnode to the second node, and whether the mobile device is transitioningfrom the first node to the second node based on the response; andprocess the request based on whether the mobile device is transitioningfrom the first node to the second node.
 20. The non-transitorycomputer-readable medium of claim 19, where: the mobile device isdetermined to be transitioning when the response indicates a user planemodify request related to the mobile device exists; and the mobiledevice is determined not to be transitioning when the response indicatesno user plane modify request related to the mobile device exists.